Merge branch 'master' of ssh://opensimulator.org/var/git/opensim

9 files changed, 314 insertions, 118 deletions

diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index f334b3d..2d02a82 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -209,3 +209,4 @@ In addition, we would like to thank:
 * The NANT Developers
 * Microsoft (.NET, MSSQL-Adapters)
 *x
+  
diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index e9d1d42..2e03874 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -151,7 +151,8 @@ namespace OpenSim.Region.Framework.Scenes
         // TODO: need to figure out how allow client agents but deny
         // root agents when ACL denies access to root agent
         public bool m_strictAccessControl = true;
-        public int MaxUndoCount = 5;
+
+        public int MaxUndoCount { get; set; }
 
         // Using this for RegionReady module to prevent LoginsDisabled from changing under our feet;
         public bool LoginLock = false;
@@ -741,6 +742,8 @@ namespace OpenSim.Region.Framework.Scenes
                 //Animation states
                 m_useFlySlow = startupConfig.GetBoolean("enableflyslow", false);
 
+                MaxUndoCount = startupConfig.GetInt("MaxPrimUndos", 20);
+
                 PhysicalPrims = startupConfig.GetBoolean("physical_prim", PhysicalPrims);
                 CollidablePrims = startupConfig.GetBoolean("collidable_prim", CollidablePrims);
 
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
index ac26be7..45bbbda 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
@@ -1119,14 +1119,6 @@ namespace OpenSim.Region.Framework.Scenes
                 parts[i].UUID = UUID.Random();
         }
 
-        // helper provided for parts.
-        public int GetSceneMaxUndo()
-        {
-            if (m_scene != null)
-                return m_scene.MaxUndoCount;
-            return 5;
-        }
-
         // justincc: I don't believe this hack is needed any longer, especially since the physics
         // parts of set AbsolutePosition were already commented out.  By changing HasGroupChanged to false
         // this method was preventing proper reload of scene objects.
@@ -2703,29 +2695,32 @@ namespace OpenSim.Region.Framework.Scenes
 //            m_log.DebugFormat(
 //                "[SCENE OBJECT GROUP]: Group resizing {0} {1} from {2} to {3}", Name, LocalId, RootPart.Scale, scale);
 
-            RootPart.StoreUndoState(true);
-
-            scale.X = Math.Max(Scene.m_minNonphys, Math.Min(Scene.m_maxNonphys, scale.X));
-            scale.Y = Math.Max(Scene.m_minNonphys, Math.Min(Scene.m_maxNonphys, scale.Y));
-            scale.Z = Math.Max(Scene.m_minNonphys, Math.Min(Scene.m_maxNonphys, scale.Z));
-
             PhysicsActor pa = m_rootPart.PhysActor;
 
-            if (pa != null && pa.IsPhysical)
+            RootPart.StoreUndoState(true);
+
+            if (Scene != null)
             {
-                scale.X = Math.Max(Scene.m_minPhys, Math.Min(Scene.m_maxPhys, scale.X));
-                scale.Y = Math.Max(Scene.m_minPhys, Math.Min(Scene.m_maxPhys, scale.Y));
-                scale.Z = Math.Max(Scene.m_minPhys, Math.Min(Scene.m_maxPhys, scale.Z));
+                scale.X = Math.Max(Scene.m_minNonphys, Math.Min(Scene.m_maxNonphys, scale.X));
+                scale.Y = Math.Max(Scene.m_minNonphys, Math.Min(Scene.m_maxNonphys, scale.Y));
+                scale.Z = Math.Max(Scene.m_minNonphys, Math.Min(Scene.m_maxNonphys, scale.Z));
+    
+                if (pa != null && pa.IsPhysical)
+                {
+                    scale.X = Math.Max(Scene.m_minPhys, Math.Min(Scene.m_maxPhys, scale.X));
+                    scale.Y = Math.Max(Scene.m_minPhys, Math.Min(Scene.m_maxPhys, scale.Y));
+                    scale.Z = Math.Max(Scene.m_minPhys, Math.Min(Scene.m_maxPhys, scale.Z));
+                }
             }
 
             float x = (scale.X / RootPart.Scale.X);
             float y = (scale.Y / RootPart.Scale.Y);
             float z = (scale.Z / RootPart.Scale.Z);
 
-            SceneObjectPart[] parts;
-            if (x > 1.0f || y > 1.0f || z > 1.0f)
+            SceneObjectPart[] parts = m_parts.GetArray();
+
+            if (Scene != null & (x > 1.0f || y > 1.0f || z > 1.0f))
             {
-                parts = m_parts.GetArray();
                 for (int i = 0; i < parts.Length; i++)
                 {
                     SceneObjectPart obPart = parts[i];
@@ -2739,7 +2734,7 @@ namespace OpenSim.Region.Framework.Scenes
 
                         if (pa != null && pa.IsPhysical)
                         {
-                            if (oldSize.X * x > m_scene.m_maxPhys)
+                            if (oldSize.X * x > Scene.m_maxPhys)
                             {
                                 f = m_scene.m_maxPhys / oldSize.X;
                                 a = f / x;
@@ -2747,7 +2742,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 y *= a;
                                 z *= a;
                             }
-                            else if (oldSize.X * x < m_scene.m_minPhys)
+                            else if (oldSize.X * x < Scene.m_minPhys)
                             {
                                 f = m_scene.m_minPhys / oldSize.X;
                                 a = f / x;
@@ -2756,7 +2751,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 z *= a;
                             }
 
-                            if (oldSize.Y * y > m_scene.m_maxPhys)
+                            if (oldSize.Y * y > Scene.m_maxPhys)
                             {
                                 f = m_scene.m_maxPhys / oldSize.Y;
                                 a = f / y;
@@ -2764,7 +2759,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 y *= a;
                                 z *= a;
                             }
-                            else if (oldSize.Y * y < m_scene.m_minPhys)
+                            else if (oldSize.Y * y < Scene.m_minPhys)
                             {
                                 f = m_scene.m_minPhys / oldSize.Y;
                                 a = f / y;
@@ -2773,7 +2768,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 z *= a;
                             }
 
-                            if (oldSize.Z * z > m_scene.m_maxPhys)
+                            if (oldSize.Z * z > Scene.m_maxPhys)
                             {
                                 f = m_scene.m_maxPhys / oldSize.Z;
                                 a = f / z;
@@ -2781,7 +2776,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 y *= a;
                                 z *= a;
                             }
-                            else if (oldSize.Z * z < m_scene.m_minPhys)
+                            else if (oldSize.Z * z < Scene.m_minPhys)
                             {
                                 f = m_scene.m_minPhys / oldSize.Z;
                                 a = f / z;
@@ -2792,7 +2787,7 @@ namespace OpenSim.Region.Framework.Scenes
                         }
                         else
                         {
-                            if (oldSize.X * x > m_scene.m_maxNonphys)
+                            if (oldSize.X * x > Scene.m_maxNonphys)
                             {
                                 f = m_scene.m_maxNonphys / oldSize.X;
                                 a = f / x;
@@ -2800,7 +2795,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 y *= a;
                                 z *= a;
                             }
-                            else if (oldSize.X * x < m_scene.m_minNonphys)
+                            else if (oldSize.X * x < Scene.m_minNonphys)
                             {
                                 f = m_scene.m_minNonphys / oldSize.X;
                                 a = f / x;
@@ -2809,7 +2804,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 z *= a;
                             }
 
-                            if (oldSize.Y * y > m_scene.m_maxNonphys)
+                            if (oldSize.Y * y > Scene.m_maxNonphys)
                             {
                                 f = m_scene.m_maxNonphys / oldSize.Y;
                                 a = f / y;
@@ -2817,7 +2812,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 y *= a;
                                 z *= a;
                             }
-                            else if (oldSize.Y * y < m_scene.m_minNonphys)
+                            else if (oldSize.Y * y < Scene.m_minNonphys)
                             {
                                 f = m_scene.m_minNonphys / oldSize.Y;
                                 a = f / y;
@@ -2826,7 +2821,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 z *= a;
                             }
 
-                            if (oldSize.Z * z > m_scene.m_maxNonphys)
+                            if (oldSize.Z * z > Scene.m_maxNonphys)
                             {
                                 f = m_scene.m_maxNonphys / oldSize.Z;
                                 a = f / z;
@@ -2834,7 +2829,7 @@ namespace OpenSim.Region.Framework.Scenes
                                 y *= a;
                                 z *= a;
                             }
-                            else if (oldSize.Z * z < m_scene.m_minNonphys)
+                            else if (oldSize.Z * z < Scene.m_minNonphys)
                             {
                                 f = m_scene.m_minNonphys / oldSize.Z;
                                 a = f / z;
@@ -2858,7 +2853,6 @@ namespace OpenSim.Region.Framework.Scenes
             RootPart.Resize(prevScale);
 //            RootPart.IgnoreUndoUpdate = false;
 
-            parts = m_parts.GetArray();
             for (int i = 0; i < parts.Length; i++)
             {
                 SceneObjectPart obPart = parts[i];
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
index 411dcc7..3f10b34 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
@@ -266,8 +266,8 @@ namespace OpenSim.Region.Framework.Scenes
         private string m_sitAnimation = "SIT";
         private string m_text = String.Empty;
         private string m_touchName = String.Empty;
-        private readonly Stack<UndoState> m_undo = new Stack<UndoState>(5);
-        private readonly Stack<UndoState> m_redo = new Stack<UndoState>(5);
+        private readonly List<UndoState> m_undo = new List<UndoState>(5);
+        private readonly List<UndoState> m_redo = new List<UndoState>(5);
 
         private bool m_passTouches = false;
         private bool m_passCollisions = false;
@@ -2368,16 +2368,20 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="scale"></param>
         public void Resize(Vector3 scale)
         {
-            scale.X = Math.Max(ParentGroup.Scene.m_minNonphys, Math.Min(ParentGroup.Scene.m_maxNonphys, scale.X));
-            scale.Y = Math.Max(ParentGroup.Scene.m_minNonphys, Math.Min(ParentGroup.Scene.m_maxNonphys, scale.Y));
-            scale.Z = Math.Max(ParentGroup.Scene.m_minNonphys, Math.Min(ParentGroup.Scene.m_maxNonphys, scale.Z));
-
             PhysicsActor pa = PhysActor;
-            if (pa != null && pa.IsPhysical)
+
+            if (ParentGroup.Scene != null)
             {
-                scale.X = Math.Max(ParentGroup.Scene.m_minPhys, Math.Min(ParentGroup.Scene.m_maxPhys, scale.X));
-                scale.Y = Math.Max(ParentGroup.Scene.m_minPhys, Math.Min(ParentGroup.Scene.m_maxPhys, scale.Y));
-                scale.Z = Math.Max(ParentGroup.Scene.m_minPhys, Math.Min(ParentGroup.Scene.m_maxPhys, scale.Z));
+                scale.X = Math.Max(ParentGroup.Scene.m_minNonphys, Math.Min(ParentGroup.Scene.m_maxNonphys, scale.X));
+                scale.Y = Math.Max(ParentGroup.Scene.m_minNonphys, Math.Min(ParentGroup.Scene.m_maxNonphys, scale.Y));
+                scale.Z = Math.Max(ParentGroup.Scene.m_minNonphys, Math.Min(ParentGroup.Scene.m_maxNonphys, scale.Z));
+    
+                if (pa != null && pa.IsPhysical)
+                {
+                    scale.X = Math.Max(ParentGroup.Scene.m_minPhys, Math.Min(ParentGroup.Scene.m_maxPhys, scale.X));
+                    scale.Y = Math.Max(ParentGroup.Scene.m_minPhys, Math.Min(ParentGroup.Scene.m_maxPhys, scale.Y));
+                    scale.Z = Math.Max(ParentGroup.Scene.m_minPhys, Math.Min(ParentGroup.Scene.m_maxPhys, scale.Z));
+                }
             }
 
 //            m_log.DebugFormat("[SCENE OBJECT PART]: Resizing {0} {1} to {2}", Name, LocalId, scale);
@@ -3166,61 +3170,62 @@ namespace OpenSim.Region.Framework.Scenes
 
         public void StoreUndoState(bool forGroup)
         {
-            if (!Undoing)
+            if (ParentGroup == null || ParentGroup.Scene == null)
+                return;
+
+            if (Undoing)
             {
-                if (!IgnoreUndoUpdate)
+//                m_log.DebugFormat(
+//                    "[SCENE OBJECT PART]: Ignoring undo store for {0} {1} since already undoing", Name, LocalId);
+                return;
+            }
+
+            if (IgnoreUndoUpdate)
+            {
+//                    m_log.DebugFormat("[SCENE OBJECT PART]: Ignoring undo store for {0} {1}", Name, LocalId);
+                return;
+            }
+
+            lock (m_undo)
+            {
+                if (m_undo.Count > 0)
                 {
-                    if (ParentGroup != null)
+                    UndoState last = m_undo[m_undo.Count - 1];
+                    if (last != null)
                     {
-                        lock (m_undo)
+                        // TODO: May need to fix for group comparison
+                        if (last.Compare(this))
                         {
-                            if (m_undo.Count > 0)
-                            {
-                                UndoState last = m_undo.Peek();
-                                if (last != null)
-                                {
-                                    // TODO: May need to fix for group comparison
-                                    if (last.Compare(this))
-                                    {
-    //                                        m_log.DebugFormat(
-    //                                            "[SCENE OBJECT PART]: Not storing undo for {0} {1} since current state is same as last undo state, initial stack size {2}",
-    //                                            Name, LocalId, m_undo.Count);
-    
-                                        return;
-                                    }
-                                }
-                            }
-    
-    //                            m_log.DebugFormat(
-    //                                "[SCENE OBJECT PART]: Storing undo state for {0} {1}, forGroup {2}, initial stack size {3}",
-    //                                Name, LocalId, forGroup, m_undo.Count);
-    
-                            if (ParentGroup.GetSceneMaxUndo() > 0)
-                            {
-                                UndoState nUndo = new UndoState(this, forGroup);
-    
-                                m_undo.Push(nUndo);
-    
-                                if (m_redo.Count > 0)
-                                    m_redo.Clear();
-    
-    //                                m_log.DebugFormat(
-    //                                    "[SCENE OBJECT PART]: Stored undo state for {0} {1}, forGroup {2}, stack size now {3}",
-    //                                    Name, LocalId, forGroup, m_undo.Count);
-                            }
+//                                        m_log.DebugFormat(
+//                                            "[SCENE OBJECT PART]: Not storing undo for {0} {1} since current state is same as last undo state, initial stack size {2}",
+//                                            Name, LocalId, m_undo.Count);
+
+                            return;
                         }
                     }
                 }
-//                else
-//                {
-//                    m_log.DebugFormat("[SCENE OBJECT PART]: Ignoring undo store for {0} {1}", Name, LocalId);
-//                }
+
+//                                m_log.DebugFormat(
+//                                    "[SCENE OBJECT PART]: Storing undo state for {0} {1}, forGroup {2}, initial stack size {3}",
+//                                    Name, LocalId, forGroup, m_undo.Count);
+
+                if (ParentGroup.Scene.MaxUndoCount > 0)
+                {
+                    UndoState nUndo = new UndoState(this, forGroup);
+
+                    m_undo.Add(nUndo);
+
+                    if (m_undo.Count > ParentGroup.Scene.MaxUndoCount)
+                        m_undo.RemoveAt(0);
+
+                    if (m_redo.Count > 0)
+                        m_redo.Clear();
+
+//                                    m_log.DebugFormat(
+//                                        "[SCENE OBJECT PART]: Stored undo state for {0} {1}, forGroup {2}, stack size now {3}",
+//                                        Name, LocalId, forGroup, m_undo.Count);
+                }
             }
-//            else
-//            {
-//                m_log.DebugFormat(
-//                    "[SCENE OBJECT PART]: Ignoring undo store for {0} {1} since already undoing", Name, LocalId);
-//            }
         }
 
         /// <summary>
@@ -3245,21 +3250,24 @@ namespace OpenSim.Region.Framework.Scenes
 
                 if (m_undo.Count > 0)
                 {
-                    UndoState goback = m_undo.Pop();
+                    UndoState goback = m_undo[m_undo.Count - 1];
+                    m_undo.RemoveAt(m_undo.Count - 1);
 
-                    if (goback != null)
+                    UndoState nUndo = null;
+    
+                    if (ParentGroup.Scene.MaxUndoCount > 0)
                     {
-                        UndoState nUndo = null;
-        
-                        if (ParentGroup.GetSceneMaxUndo() > 0)
-                        {
-                            nUndo = new UndoState(this, goback.ForGroup);
-                        }
+                        nUndo = new UndoState(this, goback.ForGroup);
+                    }
+
+                    goback.PlaybackState(this);
 
-                        goback.PlaybackState(this);
+                    if (nUndo != null)
+                    {
+                        m_redo.Add(nUndo);
 
-                        if (nUndo != null)
-                            m_redo.Push(nUndo);
+                        if (m_redo.Count > ParentGroup.Scene.MaxUndoCount)
+                            m_redo.RemoveAt(0);
                     }
                 }
 
@@ -3279,20 +3287,21 @@ namespace OpenSim.Region.Framework.Scenes
 
                 if (m_redo.Count > 0)
                 {
-                    UndoState gofwd = m_redo.Pop();
-    
-                    if (gofwd != null)
+                    UndoState gofwd = m_redo[m_redo.Count - 1];
+                    m_redo.RemoveAt(m_redo.Count - 1);
+
+                    if (ParentGroup.Scene.MaxUndoCount > 0)
                     {
-                        if (ParentGroup.GetSceneMaxUndo() > 0)
-                        {
-                            UndoState nUndo = new UndoState(this, gofwd.ForGroup);
-    
-                            m_undo.Push(nUndo);
-                        }
-    
-                        gofwd.PlayfwdState(this);
+                        UndoState nUndo = new UndoState(this, gofwd.ForGroup);
+
+                        m_undo.Add(nUndo);
+
+                        if (m_undo.Count > ParentGroup.Scene.MaxUndoCount)
+                            m_undo.RemoveAt(0);
                     }
 
+                    gofwd.PlayfwdState(this);
+
 //                m_log.DebugFormat(
 //                    "[SCENE OBJECT PART]: Handled redo request for {0} {1}, stack size now {2}",
 //                    Name, LocalId, m_redo.Count);
diff --git a/OpenSim/Region/Framework/Scenes/Tests/SceneObjectResizeTests.cs b/OpenSim/Region/Framework/Scenes/Tests/SceneObjectResizeTests.cs
index e931859..89647d6 100644
--- a/OpenSim/Region/Framework/Scenes/Tests/SceneObjectResizeTests.cs
+++ b/OpenSim/Region/Framework/Scenes/Tests/SceneObjectResizeTests.cs
@@ -62,8 +62,6 @@ namespace OpenSim.Region.Framework.Scenes.Tests
             Assert.That(g1Post.RootPart.Scale.X, Is.EqualTo(2));
             Assert.That(g1Post.RootPart.Scale.Y, Is.EqualTo(3));
             Assert.That(g1Post.RootPart.Scale.Z, Is.EqualTo(4));
-
-            Assert.That(g1Post.RootPart.UndoCount, Is.EqualTo(1));
         }
 
         /// <summary>
diff --git a/OpenSim/Region/Framework/Scenes/Tests/SceneObjectUndoRedoTests.cs b/OpenSim/Region/Framework/Scenes/Tests/SceneObjectUndoRedoTests.cs
new file mode 100644
index 0000000..96973de
--- /dev/null
+++ b/OpenSim/Region/Framework/Scenes/Tests/SceneObjectUndoRedoTests.cs
@@ -0,0 +1,184 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Reflection;
+using NUnit.Framework;
+using OpenMetaverse;
+using OpenSim.Framework;
+using OpenSim.Framework.Communications;
+using OpenSim.Region.Framework.Scenes;
+using OpenSim.Tests.Common;
+using OpenSim.Tests.Common.Mock;
+
+namespace OpenSim.Region.Framework.Scenes.Tests
+{
+    /// <summary>
+    /// Tests for undo/redo
+    /// </summary>
+    public class SceneObjectUndoRedoTests : OpenSimTestCase
+    {
+        [Test]
+        public void TestUndoRedoResizeSceneObject()
+        {
+            TestHelpers.InMethod();
+//            TestHelpers.EnableLogging();
+
+            Vector3 firstSize = new Vector3(2, 3, 4);
+            Vector3 secondSize = new Vector3(5, 6, 7);
+
+            Scene scene = new SceneHelpers().SetupScene();
+            scene.MaxUndoCount = 20;
+            SceneObjectGroup g1 = SceneHelpers.AddSceneObject(scene);
+
+            // TODO: It happens to be the case that we are not storing undo states for SOPs which are not yet in a SOG,
+            // which is the way that AddSceneObject() sets up the object (i.e. it creates the SOP first).  However,
+            // this is somewhat by chance.  Really, we shouldn't be storing undo states at all if the object is not
+            // in a scene.
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(0));
+
+            g1.GroupResize(firstSize);
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(1));
+
+            g1.GroupResize(secondSize);
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(2));
+
+            g1.RootPart.Undo();
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(1));
+            Assert.That(g1.GroupScale, Is.EqualTo(firstSize));
+
+            g1.RootPart.Redo();
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(2));
+            Assert.That(g1.GroupScale, Is.EqualTo(secondSize));
+        }
+
+        [Test]
+        public void TestUndoLimit()
+        {
+            TestHelpers.InMethod();
+
+            Vector3 firstSize = new Vector3(2, 3, 4);
+            Vector3 secondSize = new Vector3(5, 6, 7);
+            Vector3 thirdSize = new Vector3(8, 9, 10);
+            Vector3 fourthSize = new Vector3(11, 12, 13);
+
+            Scene scene = new SceneHelpers().SetupScene();
+            scene.MaxUndoCount = 2;
+            SceneObjectGroup g1 = SceneHelpers.AddSceneObject(scene);
+
+            g1.GroupResize(firstSize);
+            g1.GroupResize(secondSize);
+            g1.GroupResize(thirdSize);
+            g1.GroupResize(fourthSize);
+
+            g1.RootPart.Undo();
+            g1.RootPart.Undo();
+            g1.RootPart.Undo();
+
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(0));
+            Assert.That(g1.GroupScale, Is.EqualTo(secondSize));
+        }
+
+        [Test]
+        public void TestNoUndoOnObjectsNotInScene()
+        {
+            TestHelpers.InMethod();
+
+            Vector3 firstSize = new Vector3(2, 3, 4);
+            Vector3 secondSize = new Vector3(5, 6, 7);
+            Vector3 thirdSize = new Vector3(8, 9, 10);
+            Vector3 fourthSize = new Vector3(11, 12, 13);
+
+            Scene scene = new SceneHelpers().SetupScene();
+            scene.MaxUndoCount = 20;
+            SceneObjectGroup g1 = SceneHelpers.CreateSceneObject(1, TestHelpers.ParseTail(0x1));
+
+            g1.GroupResize(firstSize);
+            g1.GroupResize(secondSize);
+
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(0));
+
+            g1.RootPart.Undo();
+
+            Assert.That(g1.GroupScale, Is.EqualTo(secondSize));
+        }
+
+        [Test]
+        public void TestUndoBeyondAvailable()
+        {
+            TestHelpers.InMethod();
+
+            Vector3 newSize = new Vector3(2, 3, 4);
+
+            Scene scene = new SceneHelpers().SetupScene();
+            scene.MaxUndoCount = 20;
+            SceneObjectGroup g1 = SceneHelpers.AddSceneObject(scene);
+            Vector3 originalSize = g1.GroupScale;
+
+            g1.RootPart.Undo();
+
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(0));
+            Assert.That(g1.GroupScale, Is.EqualTo(originalSize));
+
+            g1.GroupResize(newSize);
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(1));
+            Assert.That(g1.GroupScale, Is.EqualTo(newSize));
+
+            g1.RootPart.Undo();
+            g1.RootPart.Undo();
+
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(0));
+            Assert.That(g1.GroupScale, Is.EqualTo(originalSize));
+        }
+
+        [Test]
+        public void TestRedoBeyondAvailable()
+        {
+            TestHelpers.InMethod();
+
+            Vector3 newSize = new Vector3(2, 3, 4);
+
+            Scene scene = new SceneHelpers().SetupScene();
+            scene.MaxUndoCount = 20;
+            SceneObjectGroup g1 = SceneHelpers.AddSceneObject(scene);
+            Vector3 originalSize = g1.GroupScale;
+
+            g1.RootPart.Redo();
+
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(0));
+            Assert.That(g1.GroupScale, Is.EqualTo(originalSize));
+
+            g1.GroupResize(newSize);
+            g1.RootPart.Undo();
+            g1.RootPart.Redo();
+            g1.RootPart.Redo();
+
+            Assert.That(g1.RootPart.UndoCount, Is.EqualTo(1));
+            Assert.That(g1.GroupScale, Is.EqualTo(newSize));
+        }
+    }
+}
\ No newline at end of file
diff --git a/OpenSim/Region/Framework/Scenes/Tests/SceneObjectUserGroupTests.cs b/OpenSim/Region/Framework/Scenes/Tests/SceneObjectUserGroupTests.cs
index c7eaff9..2b79271 100644
--- a/OpenSim/Region/Framework/Scenes/Tests/SceneObjectUserGroupTests.cs
+++ b/OpenSim/Region/Framework/Scenes/Tests/SceneObjectUserGroupTests.cs
@@ -44,7 +44,7 @@ using OpenSim.Tests.Common.Mock;
 namespace OpenSim.Region.Framework.Scenes.Tests
 {
     [TestFixture]
-    public class SceneObjectUserGroupTests
+    public class SceneObjectUserGroupTests : OpenSimTestCase
     {
         /// <summary>
         /// Test share with group object functionality
@@ -54,7 +54,6 @@ namespace OpenSim.Region.Framework.Scenes.Tests
         public void TestShareWithGroup()
         {
             TestHelpers.InMethod();
-//            log4net.Config.XmlConfigurator.Configure();
                         
             UUID userId = UUID.Parse("10000000-0000-0000-0000-000000000001");
             
diff --git a/bin/OpenSim.ini.example b/bin/OpenSim.ini.example
index b21a214..c7df7bb 100644
--- a/bin/OpenSim.ini.example
+++ b/bin/OpenSim.ini.example
@@ -97,6 +97,10 @@
     ;; from the selected region_info_source.
     ; allow_regionless = false
 
+    ;# {MaxPrimUndos} {} {Maximum number of undos avialable for position, rotation and scale changes of each prim} {} 20
+    ;; Increasing the number of undos available number will increase memory usage.
+    MaxPrimUndos = 20
+
     ;# {NonPhysicalPrimMin} {} {Minimum size of nonphysical prims?} {} 0.001
     ;; Minimum size for non-physical prims.  Affects resizing of existing 
     ;; prims.  This can be overriden in the region config file (as 
diff --git a/bin/OpenSimDefaults.ini b/bin/OpenSimDefaults.ini
index 315ffbe..9c32abd 100644
--- a/bin/OpenSimDefaults.ini
+++ b/bin/OpenSimDefaults.ini
@@ -85,6 +85,10 @@
     ;; from the selected region_info_source.
     allow_regionless = false
 
+    ; Maximum number of position, rotation and scale changes for each prim that the simulator will store for later undos
+    ; Increasing this number will increase memory usage.
+    MaxPrimUndos = 20
+
     ; Maximum size of non physical prims.  Affects resizing of existing prims.  This can be overriden in the region config file (as NonPhysicalPrimMax!).
     NonPhysicalPrimMax = 256